CCFL backlight bulb replacement

[kevinm34232]

I picked up a Hisense LTDN42V77US that had 2 seconds to black problem. The TV had been dropped, but screen was not cracked, so I thought it may have a broken bulb and was correct.

The panel is a V420H2-L06 Rev. C1

I opened 2 similar spare panels but the bulbs were thinner and too long. This bulb looks to be 920mm x 4mm. Closest I can find is a 900mm x 4mm

http://www.ccflwarehouse.com/lacclaforlcd.html

1) Does anyone know where I can find that size bulb?

2) If not, can I use the shorter one and extend the leads with some type of HV wire?

3) As a last resort, can I bypass this bulb in this circuit here inside the panel.

Thanks!

[Sevenqi]

Re: CCFL backlight bulb replacement

You can put the bottom one to the broken bulb position, the backlight is slightly darker then normal.

[attainteddragon]

Re: CCFL backlight bulb replacement

that 2cm shorter bulb will work fine, just extend your leads for it and you will be good!

[johnboy1313]

Re: CCFL backlight bulb replacement

I'm doing the same thing with a 40" but I'm using bulbs from a 37" so they're ~4cm shorter. It's not working. The inverter is going into protection on me. Your best bet is to look on Craigslist for guys advertising that they buy broken TVs and call to see if any of them have any bulbs the length you need. I fixed a 42" Sanyo that way. I picked up 3 bulbs for $25 and didn't have to worry about shipping.

[attainteddragon]

Re: CCFL backlight bulb replacement

3" is more like 7.5 cm. you also have to check the diameter to see if you can get away with it! have you checked your protection voltage to see how much it is jumping! you only have a couple of volts to play with and if the inverter is running multiple globes, you run a chance of an older globe dragging down the voltage as it ages!

[johnboy1313]

Re: CCFL backlight bulb replacement

900mm bulb vs ~860mm bulb so it is more like 4cm. The screens are measured diagonally so once trigged out, the difference in the length of the bulbs isn't as large as the difference in the size of the screens. The placement of the connections inside the panel make a difference too.

[johnboy1313]

Re: CCFL backlight bulb replacement

have you checked your protection voltage to see how much it is jumping! you only have a couple of volts to play with and if the inverter is running multiple globes, you run a chance of an older globe dragging down the voltage as it ages!

https://www.badcaps.net/forum/showthread.php?t=29580

[kevinm34232]

Re: CCFL backlight bulb replacement

Well I will try a 40" bulb and see what happens. What are you using to extend the length of the bulb some of the pink/white inverter wiring?

[budm]

Re: CCFL backlight bulb replacement

If you can use those wire with Silicone insulation which is high temp, that will be good to use.

[kevinm34232]

Re: CCFL backlight bulb replacement

This worked for me.

I used a 900mm x 3mm bulb out of a spare 40" panel. I took one of the pink/white wire inverter connectors and removed the pin termination out of the connector.

One end of the bulb slipped into that connector, the other end of the wire I soldered to the backlight assembly like the rest of them.

Its a very short piece, I didn't use silicone though I propped up the bulb in that area with one of those plastic holders.

I cannot notice any difference on the screen.

[attainteddragon]

Re: CCFL backlight bulb replacement

excellent, i usually move the globe to either the top or bottom position so it blends in better.

another one saved!